Modern building construction techniques use a number of relatively economical components to efficiently form the interior walls of a building. The wall frames typically include fabricated sheet metal components that can be easily cut to length in the field when necessary. As shown in FIG. 1, the frame includes upper and lower U-shaped support channels that are anchored to the ceiling and floor, respectively. The frame also includes a number of hollow C-shaped studs that span between the upper and lower channels at evenly spaced locations down the length of the channels. Once the wall frames are erected, the electrical wiring, plumbing, ventilation ducts, insulation, and other desired components and materials are routed through or placed within the wall frames. Drywall or paneling is then secured to the sides of the wall frames to complete the walls of the building.
The bottom ends of the studs are typically bolted or otherwise rigidly secured to the lower channel. However, in many wall constructions, the top end of the studs are not rigidly secured to the upper channel. The upper channel is anchored to the ceiling, but is not designed to rest on the studs. This type of construction enables the ceiling to move vertically or “float” above the wall. When the ceiling flexes do to an increase in load, such as by adding equipment, people or snow, the ceiling will not compress, crush or buckle the studs, drywall, paneling or other components and materials forming the wall.
During the construction of the interior walls, the wall frames are first erected to an intermediate stage of construction. During this interim stage, the upper and lower channels are anchored to the ceiling and floor, respectively, and the ends of the studs are fixed to the channels. The ends of the studs may be fixed to the channel via friction, as the studs and channels are about the same width, or the studs may be screwed or riveted to the channels at their desired locations. Electrical conduit and outlets, plumbing, heating and ventilation ducts, are then routed throughout the rooms of the building. Each stud includes one or more knockouts to allow these components to be easily routed through the stud and the wall frame. As shown in FIG. 1, the construction personnel performing this work can inadvertently bump or intentionally move the studs from their intended positions. If the studs are screwed or riveted in place, they are difficult to move and may be bent by the workers. Before the wall is completed, the fasteners securing the studs to the upper channel must be removed. If the studs are simply held in place by friction, the workers can easily move them, but the workers must take the time to realign the studs into their intended evenly spaced positions.
The acoustical or thermal insulation is then packed into the wall frame. This packed insulation will maintain the spacing and alignment of the upper end of the studs even though they are not rigidly secured to the upper channel. Once this insulation is installed, it is difficult to reposition the support studs if they are out of their desired vertical, evenly spaced positions. The electrical, plumbing and duct work will invariably result in the necessary repositioning of some studs. Still, many studs are left out of their desired position because the workers cannot easily realign them. Packing insulation between the studs can also move the studs out of position. The quick pace of modern building construction and the division of tasks aggravate this problem, so that no person or group of workers is responsible for maintaining the alignment of the studs. The end result is that the studs are often left out of place and are difficult to locate once the drywall or paneling is installed.
A problem with temporarily riveting or screwing the studs to the upper channel to maintain the desired stud alignment is that these fasteners need to be removed before the drywall or paneling is mounted to the wall frame. This is a time consuming and monotonous task. Workers can easily forget to remove one or more of the hundreds of fasteners securing the studs to the upper channel throughout the building. The wall frame is then improperly fixed to the ceiling, which can crush or buckle the studs, drywall, paneling or other wall components.
Many architects and contractors specify that slots be formed in the upper channels to align the studs without fastening them to the upper channel during the intermediate stage of construction, as shown in FIG. 2. For reasons discussed below, the bottom ends of the studs remain secured to the lower channel via friction, rivets or screws. Each slot is formed by two inwardly bent folds that abut the sides of the stud to retain the stud in its desired position. Because the studs and channel are about the same width, each stud is twisted axially to allow it to snap-fit into its corresponding slot. The twisting causes the open side of the C-shaped stud to compress so that that it will clear one of the inwardly bent folds. The studs are removed the same way. The ability to simply twist the studs to insert or remove them renders their installation or removal a relatively quick and easy task. Should an electrician, plumber or duct worker bump or temporarily move a stud out of position while performing his or her work, the worker can easily reposition the stud into its slot at the desired location. A slot having a width that is ⅛ inch larger than the width of the slot will produce this snap-fit, without causing the stud to bind with the upper channel when the wall is complete.
A problem with using slots to align and hold the studs in a wall frame is that hundreds of slots must be individually formed by hand at the construction site. Each slot requires two cuts at spaced locations to form separate vertical slits. The worker must also inwardly bend the channel to form each fold. To achieve a rectangular fold, the worker must also cut or tear the sheet metal horizontally at the end of each slit, as shown in FIG. 2a. Accordingly, these slots are labor intensive and costly to form.
Another problem with conventional slot forming methods is that the slots are inconsistently sized and shaped. Hand forming each slot produces inconsistencies in slot width and fold shape. These inconsistencies inhibit the formation of each slot to ensure that each stud properly snap-fits in place. The slits are often cut at varying distances apart, and some slits are inevitably cut angled out of vertical so that they are not parallel. The folds will also have different widths depending on where the worker grips the channel with the pliers relative to the slit. The folds are also bent to different angles relative to the rest of the channel. The result is a lack of uniformity in fold geometry and slot width. Slots often have different slot widths, such as widths a, b and c, as shown in FIG. 2. One slot is too narrow, while another is too wide. Yet, a narrow slot will not receive a stud, or it will hold the stud too tightly so that it cannot be easily inserted or removed. Narrow slots can also cause the studs to bind against the upper channel during use, which can damage the stud and wall. A slot that is too wide will not properly retain the stud, so that the stud can fall out or be easily bumped out of its slot.
A further problem is that the slits are not made to a consistent length or depth. Slits that are too long will unnecessarily weaken the channel. Slits that are too short will create folds that are not strong enough to retain the stud.
A still further problem with forming the slots is that at least two different hand tools are needed to create each slot. First, a cutting tool is used to cut the sides of the channel at the desired locations for the two slits. Once the slits are cut, a second hand tool such as a pair of pliers is used to bend and tear the channel to form two inwardly bent folds. The worker must pick up, use, and put down each tool hundreds of times. If the worker makes all the slits first and later comes back to bend each of the folds, the worker must retrace his or her path through the entire building. This effectively doubles the amount of work they must perform.
A still further problem in forming slots into the channel is that conventional bending tools, such as a pair of pliers, do not enable a worker to easily bend and tear the folds to a consistent shape or geometry. A conventional pair of pliers has no guide to align and grip the sheet metal a specific distance from an adjacent slit. As a result, some folds are wider than others. A conventional pair of pliers also has no guide to enable the worker to correctly tear the channel to form a rectangular fold having a specific width, or bend the fold to a consistent angle relative to the vertical side of the channel. Accordingly, the shape or geometry of the folds and the width of the slots will vary.
A still further problem in forming the slots is that they are not efficiently formed by conventional cutting and bending tools. The worker must first align the cutting tool perpendicular to the vertical side of the channel, and then cut the side to an appropriate depth. The desired distance between the cuts of each slot must be measured prior to making the second cut. The worker must then pick up a bending tool to form the folds. The folds must be shaped to the same desired geometry and bent to the same desired angle. These steps must be repeated several hundred times. Each step takes time, and adds to the cost of the wall.
A still further problem with many conventional cutting tools is that they are difficult to use to cut the metal channel. A tool with small handles will require a great deal of hand strength to make the cuts in thicker gauge channels. A worker can become fatigued making the hundreds of cuts needed to form the channels throughout the building, particularly for thicker gauge channels, and can lead to inconsistencies in the formation of the slots. Yet, a tool with long handles can be unwieldy, especially when the slots are being formed in an upper channel several feet above the worker. The worker can easily crush the channel when aligning or stroking the tool, particularly for thinner gauge channels.
A still further problem with many conventional cutting tools is that their blades will quickly dull when cutting thicker gauge channels. The cutting blades cannot be easily removed and replaced with sharp blades. Instead, the entire tool must be set aside for sharpening or discarded. Thus, the costs associated with using these types of cutting tools is needlessly inflated.
The present invention is intended to solve these and other problems.